What causes a SPN 797 code?

SPN 797 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a SPN 797 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 797 active.

How do I fix SPN 797?

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

J1939 SPN

SPN 797

J1939 SPN 797 — Engine Management parameter

What it means

SPN 797 indicates a failure or corruption in the Engine Management Parameters stored within the Engine Control Module (ECM). This is a memory-checksum or configuration error.